chronic yet sporadic wet cough/dry cough

I am a 55 yo female, previous smoker who was on Phen/fen for about 2 years and then Vioxx, both of which are now off the market.  I have sleep apnea, copd, pulmonary htn, reactive airways with asthma and allergies.  I spent the better part of Dec, Jan & Feb of this year with a terrible sinus infection and nasal infection.  I was treated with antibiotics, steroids, inhalers, nasal and asthma inhalers.  Finally, in March the sxs disappeared but I began having this chronic wet cough, which makes me cough violently to the point of gagging with dry heaves and sometimes actually throwing up.  The drainage in my throat and nasal passagesis perfectly clear and basically makes me feel like I am drowning.  The "attacks" can happen at any time and usually 5 to 10 times a day.  Sometimes, the reaction will be just the opposite; my throat gets very dry and makes me cough, which then brings on the sinus drainage and makes it worse.  These coughing spells most always last 5 to 10 minutes and are really affecting my normal daily routines.  The coughing happens when I awake in the morning, making me late for work.  Then at the office, not only do I keep myself from getting my work done but I am driving the other 30 ladies nuts, not just the coughing but the gagging, clearing my throat, etc... I used to step outside for fresh air but the allergies make it worse and the coughing weakens my bladder, so I am basically confined to the restroom to get away from everyone else, to keep from wetting myself and I have a place to throw up and spit and blow my nose.  Also, the cough wakes me at all hours of the night. I am now on Zyrtec, two different nasal inhalers and a mucous drying agent.  This helped for about a week but now I am back to the same old coughing, gagging, etc. I also have htn, hyperlipidemia, hypercholesterolemia, heart valve disorder, GERD, hypersomnolence, and now hyperglycemia... Do you think I just need to be taken out to pasture, or is there relief at the end of the tunnel?  I do take a lot of medicine, could the medicines cause this?